<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
		
		<script>
			"use strict"
			
			var arr = [3, 2, 7, 6, 3, 9, 2, 3, 6]
			console.log(arr.indexOf(2))
			console.log(arr.lastIndexOf(2))
			arr.forEach(function(item, index){
				console.log(item, index)
			})
			var arr1 = arr.map(function(item, index){
				return item + 10
			})
			console.log(arr1)
			var arr2 = arr.filter(function(item, index){
				return item > 3
			})
			console.log(arr2)
		</script>
	</body>
</html>
